Answer:
7374.4
Explanation:
I took the test
(filler so I can post)
A 700-gram grinding wheel 22.0 cm in diameter is in the shape of a uniform solid disk. (We can ignore the small hole at the center.) When it is in use, it turns at a constant 215 rpm about an axle perpendicular to its face through its center. When the power switch is turned off, you observe that the wheel stops in 50.0 s with constant angular acceleration due to friction at the axle.
What torque does friction exert while this wheel is slowing down?
Solution :
Given :
Mass of grinding wheel, m = 700 g
= 0.7 kg
Diameter of the grinding wheel, d = 22 cm
= 0.22 m
Radius of the grinding wheel, r = 0.11 m
Initial angular velocity of grinding wheel, [tex]$\omega_0$[/tex] = 215 rpm
[tex]$=215 \ rpm \times \frac{2 \pi \ rad}{1 \ rev}\times \frac{1 \ min}{60 \ s}$[/tex]
where, [tex]$\pi = \frac{22}{7}$[/tex]
Time taken to stop, t = 50 s
Final angular velocity is [tex]$\omega$[/tex] = 0
Angular acceleration of the grinding wheel is given by :
[tex]$\alpha = \frac{\omega-\omega_0}{t}$[/tex]
[tex]$=\frac{0-215 \ rpm \times \frac{2 \pi \ rad}{1 \ rev}\times \frac{1 \ min}{60 \ s}}{50 \ s}$[/tex]
[tex]$=-0.45 \ rad/s^2$[/tex]
Magnitude of the angular acceleration of grinding wheel [tex]$\alpha$[/tex] [tex]$=-0.45 \ rad/s^2$[/tex]
Moment of inertia of the grinding wheel (solid disk),
[tex]$I=\frac{1}{2}mR^2$[/tex]
[tex]$=\frac{1}{2} \times 0.7 \times 0.11^2$[/tex]
[tex]$=4.235 \times 10^{-3} \ kgm^2$[/tex]
Torque exerted by friction while the wheel is slowing down is
[tex]$\tau = I \alpha$[/tex]
[tex]$=4.235 \times 10^{-3} \times 0.45$[/tex]
[tex]$=1.90 \times 10^{-3} \ Nm$[/tex]
an object is moving at 60m/s and has a mass of 5 kg what is its momentum
Answer:
300
Explanation:
the momentum is 300
p=mv
p=5×60
5×60 =300
what term is used to describe the block of organs (heart, lungs, liver, kidneys and spleen) that are removed during the autopsy?
The term used to describe the block of organs that are removed during the autopsy is Thoracic organs.
The organs that are removed during autopsy include:
Thoracic organs;Cervical organs, and Abdominal organsThe thoracic cavity contains organs and tissues that function in the respirator, cardiovascular, nervous and digestive system.
These thoracic organs include the following;
heart, lungs, liver, kidneys and spleen.Thus, we can conclude that the term used to describe the block of organs that are removed during the autopsy is Thoracic organs.
Learn more here:https://brainly.com/question/25087653
Which statement best explains why objects are pulled toward Earth’s center?
Answer:
Earth has a much greater mass than objects on its surface
On Apollo Moon missions, the lunar module would blast off from the Moon's surface and dock with the command module in lunar orbit. After docking, the lunar module would be jettisoned and allowed to crash back onto the lunar surface. Seismometers placed on the Moon's surface by the astronauts would then pick up the resulting seismic waves.
Find the impact speed of the lunar module, given that it is jettisoned from an orbit 110 km above the lunar surface moving with a speed of 1600 m/s .
My Approach:
Ei = Ef
1/2*m*vi2 - (G*m*ME)/(radius of moon + orbital distance) = 1/2*m*vf2 - (G*m*ME)/r
=> (0.5 * m * 16002) - (6.67 * 10-11 * 7.35*1022 * m/(1737.4*103 +180*103) = (0.5*m*v^2) - (6.67*10-11 * 7.35*1022 * m/(1737.4*103 )
Answer:
Following are the solution to the given question:
Explanation:
For crashing speed, we can use energy conservation:
kinetic energy [tex]= \frac{1}{2}\times m \times v^2[/tex]
potential energy [tex]= -\frac{GMm}{r}[/tex]
moon mass[tex]= 7.36\times 10^{22} \ kg[/tex]
Radius[tex]= 1738\ km[/tex]
[tex]\to (K + U) \ orbit = (K + U)\ crash\\\\\to \frac{1}{2}\times m \times v_o^2 - \frac{GMm}{(1738000 + 110000)} \\\\ \to \frac{1}{2}\times m \times vc^2 - \frac{GMm}{1738000}[/tex]
Calculating the mass drop for the leave:
[tex]\to \frac{vo^2}{2} - \frac{GM}{1848000}\\\\ \to \frac{vc^2}{2} - \frac{GM}{1738000}[/tex]
Solve the value for
[tex]vc = \sqrt{(vo^2 +2\times GM \times(\frac{1}{1738000} - \frac{1}{1848000}))}\\\\vc = \sqrt{(1600^2 +2\times 6.67\times 10^{-11} \times 7.36 \times 10^{22}\times (\frac{1}{1738000} - \frac{1}{1848000}))}\\\\vc = 1701 \ \frac{m}{s}\\\\[/tex]
The approach is correct but misrepresented in replacing 180 km instead of 110 km.
PLEASE HELP
Which of the following are examples of gravity in action? Select all that apply.
A. an earthquake
B. a planet orbiting the sun
C. a ball flying through the air
D. precipitation falling to Earth
What are applications of zeroth law of thermodynamics?
Answer:
Applications of zeroth law of thermodynamics:
1. When we get very hot food, we wait to make it normal. In this case, hot food exchanges heat with surrounding and brings equilibrium.
2. We keep things in the fridge and those things come equilibrium with fridge temperature.
3. Temperature measurement with a thermometer or another device.
4. In the HVAC system, sensors or thermostats are used to indicate temperature. It always comes in a thermal equilibrium with room temperature.
5. If you and the swimming pool you’re in are at the same temperature, no heat is flowing from you to it or from it to you (although the possibility is there). You’re in thermal equilibrium.
The shortest pipe in a particular organ is 1.23 m.
Determine the frequency (in Hz) of the ninth harmonic (at 0°C) if the pipe is closed at one end.
Hz
Answer:
The 9th harmonic is 1,010.67 Hz.
Explanation:
Given;
length of the pipe, L = 1.23 m
speed of sound at 0°C = 331.5 m/s
A pipe closed at one end is known as a closed pipe;
The wavelength of the sound for the first harmonic is calculated as;
L = Node ------ > Antinode
[tex]L = \frac{\lambda }{4} \\\\\lambda = 4L[/tex]
First harmonic: [tex]F_0 = \frac{V}{\lambda} = \frac{V}{4L}[/tex]
The wavelength of the sound for the first harmonic is calculated;
L = Node ----> Node + Node ------> Antinode
[tex]L = \frac{\lambda}{2} + \frac{\lambda}{4} = \frac{2\lambda+\lambda}{4} = \frac{3\lambda}{4} \\\\\lambda = \frac{4 L}{3}[/tex]
Second harmonic: [tex]F_1 = \frac{V}{\lambda} = \frac{3V}{4L}[/tex]
F₁ = 3F₀
The increment from F₀ to F₁ is 1 to 3; (odd number).
(1, 3, 5, 7, 9, 11, 13, 15, 17, 19..... n+2, where n is odd number)
The 9th harmonic = F₈
F₈ = 15F₀
[tex]F_8= 17(F_0) = 15 (\frac{V}{4L} )\\\\F_8 = 15(\frac{331.5}{4\times 1.23} )\\\\F_8 = 1,010.67 \ Hz[/tex]
Therefore, the 9th harmonic is 1,010.67 Hz.
The frequency of the 9th harmonic if the pipe is closed at one end is 605.48 Hz.
Based on the given information,
• The length (l) of the shortest pipe given is 1.23 m.
The speed of sound at 0 degree C is,
[tex]V = 331\sqrt{1+\frac{T}{273} } \\V = 331\sqrt{1+\frac{0}{273} } \\V = 331 m/s[/tex]
Now the condition is that the pipe is closed at one end. The formula to use in the given case is,
[tex]fn = \frac{nv}{4l} \\[/tex]
Here l is the length of the organ pipe.
Now the frequency of the 9th harmonic will be,
[tex]f9 = \frac{9v}{4l} \\\\f9 = \frac{9*331}{4*1.23} \\f9 = 605.48 Hz[/tex]
Thus, the frequency of the 9th harmonic if the pipe is closed at one end is 605.48 Hz.
To know more about:
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a student throws a 140 g snowball at 8.5 m/s at the side of a schoolhouse, where it hits and sticks. what is the magnitude of the average force on the wall if the duration of the collision is .16 s?
Answer:
7.4375N
Explanation:
According to Newtons second law
F = ma
m is the mass = 140g = 0.14kg
Get the acceleration
v = u + at
8.5 = 0+0.1a
a = 8.5/0.16
a = 53.125m/s²
Get the required force
F = 0.14 * 53.125
F = 7.4375N
Hence the magnitude of the average force on the wall is 7.4375N
What kind of story would a Romantic audience find MOST appealing?
A. science fiction or futuristic worlds
B. a comedy or something light-hearted
C. one based on Christian morals and piety
D. something where a person disappears in nature
Which type of wave displaces the particles of the medium parallel to the direction on which the wave travels?
Longitudinal waves
In a longitudinal wave the particles are displaced parallel to the direction the wave travels.
is being a plat 2 in rainbow 6 siege a good rank?
Answer:
In a way it does, but overall, there are many factors that affect your rank. In general, and talking about the average Platinum II, they are pretty decent according to casual player standards.
Explanation:
A heating coil operates on 220 V if it draws 15.0 A. Find it's resistance
Answer:
R ≈ 15 ohms
Explanation:
Using ohm's law equation,
I = V/R, to solve for the resistance of the heating coil.
R = V/I
Known:
V = 220 v = 220 kgm^2s^-3A^-1
I = 15 A
Unknown:
R =?
Solution:
R = (220 kgm^2s^-3A^-1)/ 15.0 A
R = 14.6 kgm^2s^-3A^-2
R ≈ 15 kgm^2s^-3A^-2
R ≈ 15 ohms
⦁ Determining the magnetic flux, A rectangular piece of stiff paper measures 10 cm x 5 cm. You hold the piece of paper in a uniform magnetic field that has a magnitude of 4.0 x10-3 T For each situation below, - sketch a diagram showing the magnetic field and the paper, - determine the magnitude of the magnetic flux through the paper, when the magnitude of the flux is (a) maximized (b) minimized (c) halfway between its maximum and minimum value, when the angle between the magnetic field lines and the area normal vector is 300
Answer:
jguewjdofe
Explanation:
HELP ME PLEASEE I NEED HELP CLICK HERE
Answer:
Bacteria: Unicellular organisms that can cause disease in living things
Plant: A multicellular organism that makes it's own food
Animal: A multicellular organism that does not make it's own food
A sprinter accelerates at 8mps, he weights 850 grams. What
force is he exerting?
Consider the situation in which three identical spheres of clay are launched simultaneously, one along each possible path. All three spheres of clay are launched with the same initial linear speed and collide with the rod at the same time. The time of collision with the rod for each sphere is time t0. Which of the following predictions is correct about the motion of the system containing the rod and all three spheres of clay immediately after the collision?
a. The system will rotate in the clockwise direction with a constant angular speed.
b. The system will rotate in the counterclockwise direction with a constant angular speed.
c. The system will rotate in the clockwise direction with a changing angular speed.
d. The system will rotate in the counterclockwise direction with a changing angular speed.
Answer:
a. The system will rotate in the clockwise direction with a constant angular speed.
Explanation:
As all the clay is identical sphere and there will be hence same mass 'm' for all three clay spheres. Now their identical speed 'v' and collision time [tex]$'t_0'$[/tex] are also same. So all the spheres will exert same force F on the rod.
[tex]$f=\frac{mv}{t_0}$[/tex]
Force exerted by the clay Z on rod is passing through pivot, so no torque will be produced.
Now clay X will collide at near distance from pivot than that of clay Y.
So clay Y will produce more torque than clay X. So clay Y will give more clockwise torque. So rod will rotate clockwise.
Now in any impact because net force and net torque are zero (because in impact torque and force occurs in equal and opposite pairs). So net angular momentum will be conserved and hence angular speed will be constant.
Therefore it is clear that option (a) is correct.
0)
A-B-C-D-E
Describe the mass of the reactants and products given the balanced chemical reaction
A)
The mass of the products is 2/3 that of the reactants.
B)
The mass of the reactants equals the mass of the products.
C)
The mass of the reactants is less than the mass of the products.
D)
The mass of the reactants is greater than the mass of the products.
Answer:
D)
The mass of the reactants is greater than the mass of the products.
The owner of a van installs a rear-window lens that has a focal length of -0.304 m. When the owner looks out through the lens at a person standing directly behind the van, the person appears to be just 0.237 m from the back of the van, and appears to be 0.343 m tall. (a) How far from the van is the person actually standing
Answer:
[tex]p =-1.03[/tex]
Explanation:
From the question we are told that:
Focal length of lens [tex]f=-0.304 m[/tex]
Image distance [tex]q=0.237 m[/tex]
Height of image [tex]H_i=0.343[/tex]
Generally the lens equation is mathematically given by
[tex]\frac{1}{f} = \frac{1}{q} - \frac{1}{p}[/tex]
Where [tex]p[/tex] is Subject
[tex]p = \frac{(qf) }{(f - q)}[/tex]
[tex]p = \frac{(-0.237)(-0.304)) }{((-0.304) - (0.237))}[/tex]
[tex]p =-1.03[/tex]
Therefore the distance between the person and the car is
[tex]p =-1.03[/tex]
A body starts from rest and travels ‘s’ m in 2nd second, than acceleration is.
1) 2s m / s2 2) 3 s m / s2 3) 23 s m / s2 4) 32 s m / s2
Answer:
3m
Explanation:
A 70- kg bicycle rides his 9.8- kg bicycle with a speed of 16 m/ s. What is the magnitude of the braking force of the bicycle come to rest in 4.0 m?
Answer:
F = -319.2 N
Explanation:
Given that,
The mass of a bicyclist, m = 70 kg
Mass of the bicycle = 9.8 kg
The speed of a bicycle, v = 16 m/s
We need to find the magnitude of the braking force of the bicycle come to rest in 4.0 m.
The braking force is given by :
[tex]F=ma\\\\=\dfrac{m(v-u)}{t}\\\\=\dfrac{(70+9.8)(0-16)}{4}\\\\=-319.2\ N[/tex]
So, the required force is 319.2 N.
How much energy must the brakes absorb to bring a 1200kg car from 30m/s to 15 m/s?
Which type of electromagnetic radiation is used to keep food warm?
O A. Infrared radiation
O B. Visible light
O C. Gamma rays
D. X-rays
Answer:
A. infrared
Explanation:
Heat lamps used to keep foods warm are infrared on the light spectrum
3. An object has 90,000 J Kinetic energy and is moving at 12m/s. What is the objects mass?
Star X has an apparent magnitude of 1. Star Y has an apparent magnitude of 4. Both stars are in the same star cluster. Which star is more intrinsically luminous and by what factor
Answer:
Explanation:
From the given information:
Since both stars are in the same cluster, the magnitude and luminosity relationship can be calculated as:
[tex]m_1 - m_2 = -2.5 log _{10} (\dfrac{L_1}{L_2})[/tex]
Given that;
m_1 = 1 and
m_2 = 4
Therefore,
[tex]1 - 4 = -2.5 log _{10} ( \dfrac{L_1}{L_2})[/tex]
[tex]3 = -2.5 log _{10} ( \dfrac{L_1}{L_2})[/tex]
Making [tex]\dfrac{L_1}{L_2}[/tex] the subject of the formula:
[tex]\implies \dfrac{L_1}{L_2}= 10^{(\dfrac{3}{2.5})}[/tex]
=15.84
≅ 16
Hence, we can conclude that star X is more luminous by a factor of 16
11.Electricity is made at a power plant by huge
(C). Coil
(D). Wire
(A). Motor
(B). Generator
government as an academic field of study
Answer: True
Explanation:
Government as an academic field of study refers to the study of political institutions, processes and theories taught in schools, colleges and higher institution of learning. It is called Political Science in higher institution.
8. Which element will most likely form an ionic bond with chlorine?
A. O
B.N
C.S
D.K
The fictional rocket ship Adventure is measured to be 65 m long by the ship's captain inside the rocket.When the rocket moves past a space dock at 0.5c. As rocket ship Adventure passes by the space dock, the ship's captain flashes a flashlight at 1.20-s intervals as measured by space-dock personnel.
Required:
How often does the flashlight flash relative to the captain?
Answer:
1.04 s
Explanation:
The computation is shown below:
As we know that
t = t' × 1 ÷ (√(1 - (v/c)^2)
here
v = 0.5c
t = 1.20 -s
So,
1.20 = t' × 1 ÷ (√(1 - (0.5/c)^2)
1.20 = t' × 1 ÷ (√(1 - (0.5)^2)
1.20 = t' ÷ √0.75
1.20 = t' ÷ 0.866
t' = 0.866 × 1.20
= 1.04 s
The above formula should be applied
An object accelerates at a=20m/s/s and reaches a final speed of v=5m/s. How is this possible? *
A)Trick question, it has to reach 20m/s at a minimum
B) It accelerated for 0.25s
C) Something slowed it down.
Answer:
B) It accelerated for 0.25s
Explanation:
Given the following data;
Acceleration = 20 m/s²
Final velocity, v = 5 m/s
Initial velocity, u = 0 m/s
To find the time, we would use the first equation of motion;
V = u + at
Substituting into the formula, we have;
5 = 0 + 20t
5 = 20t
Time, t = 5/20
Time, t = 0.25 seconds